Many of the Altcoins are available for less than a penny and even more are available for less than a dollar. Cryptopia is a smaller exchange where many of these cheaper altcoins may be found. Once the coins gain some traction and become available on the larger exchanges like Bittrex, they often enjoy an immediate price increase, so there is some advantage to finding these alts before they are available on the larger exchanges.
Yobit is another exchange which has many coins trading for as low as 1 satoshi. You may get lucky here and invest in a coin during the early stages. I have found, however, that you must be careful on this exchange. I recently had a coin which I have been unable to withdraw because the wallet is constantly “under maintenance”. I have seen other traders with the same complaint. Their advice was to purchase tiny amounts initially in order to concern there are no problems with the wallet. This may be risky and not worthwhile, but occasionally you will have an opportunity to invest in a really potentially great coin for 1 satoshi.
I have done this a few times and was able to withdraw the coin which eventually turned a nice profit. I do. however wish I had known about the withdrawal problem before trading on the Yobit Exchange. This is just my personal experience with this exchange. I prefer Cryptopia if the altcoin is available for purchase there.
You can always see where the coin is available for purchase on Coinmarketcap.com Click on the markets button and a list of exchanges will be displayed. You will also see a list of pairings showing you whether you need Bitcoin to buy the altcoin, or if you can buy with Litecoin or Ethereum. This is important because the Bitcoin fees have become so high that it may prove to be cost prohibitive for smaller investments. The Litecoin fees are usually much lower. When Litecoin is an alternative, you may purchase Litecoin at Coinbase and simply transfer it to your wallet on exchanges like Cryptopia.